With continuous development of information and communications technology (ICT), human activities in the physical world increasingly penetrate a digital world. People make friends and establish circles of friends by using social networks; post personal opinions on social events by using Microblog to form We Media and build personal public images; obtain various goods and services through online shopping; participate in personal assets management by using network banks; record and share emotions by taking pictures or shooting videos anytime and anywhere by using personal mobile phone terminals; and sense their physical sign data by using wearable terminals to monitor their health. Further popularization of mobile terminals and the mobile Internet results in an explosive increase of data generated during activities of users on various data platforms, and massive data is distributed over digital life of users.
Behind such user data, there are various types of information representing features of individuals in the physical world, such as interests, hobbies, opinions, habits, families, and health. However, various dimensions of user data generated by various data sources is disperse and cannot be sufficiently mined.